If you listen to the first 40 seconds or so of Veridis Quo by Daft Punk, you'll probably feel like you have a pretty good idea of the beat of the song, each of the chords starting on the first beat of each bar. Then at about 40 seconds the drums fade in and you (or at least I) discover that you were wrong; what you thought were downbeats were really upbeats and vice versa.

There's a similar but maybe even more pronounced effect in Pyramid Song by Radiohead, where it's hard to even pin down what's going on beat-wise until about 2:15 when the drums come in and you realize that what you thought were five repeating quarter notes separated by a weird rest are really dotted quarter notes.

Is there a word for this kind of weird sort of beat ambiguity that is resolved when a rhythm instrument comes in? Can you come up with any other examples of this?

I Like Init-Beat Ambiguity. Thanks for letting me chime in. This is the first time I ever tried my hand at coining a term.
–
Rene MarceloJun 8 '12 at 22:56

Isn't it funny---when listening to the Daft Punk song, I tried to hear the chords as coming on the down beat, but that disoriented me, so I started to hear them anticipating the beat, and lo! that's exactly where the beat turned out to be. I guess we all hear these things differently.
–
Alex BassonJun 13 '12 at 13:18

Ozric Tentacles always love to mess with rhythm. One example: Akasha starts with the beat a bit in the air, then about 0:30 - you were wrong. At about 0:57 - no you were wrong at 0:30. See also their "The Sacred Turf". Pop sometimes does it too: 3 words (Cherl Cole ft will i am) at 0:16 erm... at 0:45 no more doubt.. (Great post, I love music that confuses me, and lots of good examples in responses. Thanks.)
–
AndrewCSep 14 '12 at 0:48

Sometimes, the ambiguity arises from an initial impulse that may or may not be interpreted as an anacrusis (i.e. pickup). Jieun Oh shows an example of this in the Korean national anthem.

From the examples in my music collection, I see it occurring when the syncopated inner tracks start first: see Gentle Giant's "So Sincere" (from "Free Hand") which simply omits the downbeat for the first few measures, and Jamiroquai's "Cosmic Girl" (from "Traveling Without Moving").

I can't resist mentioning Squarepusher's "Coopers World" (from "Hard Normal Daddy"). Though it's not quite the pattern you mention, it does have a similar deception: it does just about everything possible to convince you it's anything but the straight-up 4/4 that the hi-hats immediately establish. Here the music floats without clear downbeat for almost a minute, though with plenty of false kicks and syncopation to throw you off balance.

I believe this effect is called "turning the beat around". There are examples all through rock music. I've heard this term frequently applied to certain songs by the Rolling Stones and Led Zeppelin. [Note that this effect has nothing to do with the song entitled "Turn the Beat Around", which was a hit for Vicki Sue Robinson in 1976 and for Gloria Estefan in 1994.]

I'm not sure if there's an official term for it, but I guess it could be considered a form of syncopation, which is an unexpected disruption of the regular rhythm due to placement of stresses or accents where they wouldn't normally occur. The main difference is that, while syncopation usually refers to a temporary change in the middle of a musical piece that disrupts the established rhythm, in the cases you describe it's the initial absence of a strong rhythm instrument that leads you to make an assumption about the tempo, time signature and/or beat structure of the piece, which is then disrupted when a rhythm instrument finally does come in.

Another example of this that I found is American Baby by The Dave Matthews Band. The guitar riff initially seems to begin on beat 1, but then turns out to start on beat 2 instead.